1. Field of the Invention
The present invention relates to a method for producing an optical film, an optical film, and an image display.
2. Description of Related Art
For various image displays such as a mobile phone, a PC monitor, a liquid crystal television, and the like, liquid crystal displays (LCDs) with high contrast utilizing birefringence are used. In these years, definition of LCDs is getting higher and the application thereof covers a broad spectrum, so that improvement of display qualities of LCDs such as increase in a viewing angle, and the like is required. For the increase in a viewing angle, for example, an optical film having a refractive index distribution satisfying nx>nz>ny is used. As a method for producing the optical film, a method is proposed in which an optical film is produced by forming a laminate by attaching a shrinkable film on one side or both sides of a resin film through an acrylic pressure sensitive adhesive agent or the like, and subjecting the laminate to a heat stretching treatment while imparting a shrinking force to the laminate in a direction orthogonal to the stretching direction (JP5-157911 A).